High-selective sensitive NH3 gas sensor: A density functional theory study

P-type metal oxide semiconductor with extraordinary surface reactions is highly active for gas sensing reactions. However, presenting large active sites in materials surface for sensing reactions is a great challenge. Here, we report a strategy to fabricate Co3O4 hexagonal platelets and characterize the adsorption of ammonia (NH3) by using density-functional theory (DFT) calculations. The as-prepared Co3O4 hexagonal platelets exposed by (112) crystal plane shows high selectivity and sensitivity to NH3 at room temperatures. In addition, fantastic reproducibility of the device is also demonstrated. Such alluring sensing performances can be attributed to unique size, structure, and surface arrangement on the Co3O4 platelets that facilitate the NH3 adsorption and interface interaction. The present studies provided a new insight into improving the selectivity of gas sensors by designing special crystal-facets exposure in the nanomaterials surface matrix. (C) 2018 Elsevier B.V. All rights reserved.